George eehfuss



(No Model.) v

G. REHFUSS.

DRILL CHUCK.

No. 256,739. Patentd Apr. 18,1882.

UNTTED STATES PATnNT Ormea.

GEORGE REHFUSS, OF PHILADELPHIA, PA., ASSIGNOR TO HIMSELF, JOHN GEORGE REHFUSS, AND MARTIN O. REHFUSS, ALL OF SAME PLAGE.

DRILL-CHUCK.

SPECIFICATION forming part .of Letters Patent No. 256,739, dated April 18, 1882.

Application filed December 22,*1881. (No model.) f

To all whom it may concern:

Be it known that I, GEORGE REHFUss, a citizen of the United States,residing in Philadelphia, Pennsylvania, have invented certain Improvementsin Drill-Chucks, of which the following is a specification.

My invention relates to that class of chucks in which elastic jaws are caused to grip the stein of a drilling or other tool by forcing the ro conical end of a nut adapted to the threaded body of the chuck against the said jaws, my

improved chuck being constructed in the peculiar manner fully described hereinafter, with the view ot'iirmlygrippingthe cylindrical stern i5 of a tool or instrument, and for the purpose ot maintaining the truth ot' the several parts ot the chuck and ofthe said stem ofthe tool concentrically in respect to each other.

In the accompanying drawings, Figure l is a sectional view of my improved chuck; Fig. 2, a section of the body of the chuck; Figs. 3 and 4, perspective views of the slotted sleeves detached from the body, and Fig. 5 a view et the chuck with a single sleeve.

A represents the body ot the chuck, which may be constructed in any suitable manner for attachment to the spindle ofthe head-stock of a lathe such as is used by dentists, jewelers, and others; or the body of the chuck may forni part ot' the lathe-spindle, or part of the spindle of a polishing, grinding, or drilling machine; and B is the cylindrical stem of any tool or instrument adapted to the chuck.

It should be understood in the outset that the different tools which have to be confined to the chuck must have stems ot' the same or nearly the same diameter.

The body A of the chuck has a recess, lV, for receiving the sleeves D and G, the former 4o having` a conical termination, d, which bears against the conical shoulder c in the said recess, the internal diameter ofthe sleeve being such that when not under end pressure it will freely admit the stem B, for slitsf (three in the present instance) are made in the sleeve to forrnjaws for tightly gripping the said stem, as explained hereinafter.

The recess Win the spindle is preferably continued at w beyond the conical shoulder c, so that the stem B may extend into this continuation ofthe recess; or the spindle may have an opening throughout its entire length, it' desired.

The cylindrical portion of the sleeve D is arranged to lit loosely within thecylindrical portion of the outer sleeve, G, which has a conical termination, h, and slitsf, similar to those of the sleeve D, the end of the sleeve G being beveled and adapted to bear against the beveled shoulder m on theinner sleeve, D. These 6o beveled bearin gs are important features of my invention, as will be seen hereinafter.

The nut H has a cylindrical portion, g, and a conical portion, t, the interior of the latter being adapted to the conical termination h ot the sleeve G. The cylindrical portion of the nut is threaded internally, and is adapted to the screw-thread fv on the body of the chuck. This screw-thread, however, does not extend to the end ofthe body,a portion, y, of the lat- 7o ter being plain, and this plain portion is arranged to fit very accurately in the portion u of the nut. When this nut is screwed tightly' onto the body of the chuck the slotted portion of the sleeve Gmust necessarily be contracted simultaneously with the contraction of the slotted portion ofthe sleeve D, and hence the stem B must be gripped between two sets of jaws.

It should be here understood that a chuck 8o of the class to which my invention relates has been made with a sleeve having jaws at both ends; but the two sets of jaws on one sleeve involved the necessity ot' making the latter of great length,in order that thejaws might have the desired elasticity, and the long sleeve demanded such a projection of thenut and body of the chuck as tocause unsteadiness-a defect which I obviate by making one set ofjaws on one sleeve and another set on another sleeve 9o. and adapting a portion of one to fit into the other, as described.

It will be seen that the slots in the sleeves are so long that the sleeve D can be contracted throughout the greater portion of its length, as indicated by the dotted line 3, Fig. l, and the sleeve G throughout the length indicated by the dotted line 4, so that the stein will be gripped from the end c of the sleeve G to the end g ofthe sleeve D, or to theextentindicated roo by the dotted line 5, the gripping being` of course more determined at the conical portions of the sleeves, but, owing to the length of the slots,having more or less effect throughout the length indicated.

It is important that the nut ll should always be coneentrically true on the body of the chuck, and reliance cannot always be placed on screw-threads for the attainment of this desired truth; hence the snug fitting previously referred to of the portion u of the nut on the plain portion y ofthe body of the chuck, which insures the truth of the nut, even if there should be a slightY looseness of the screw. Vlien the nut is screwed tight and end-pressure is applied to the sleeves the beveled bearings m a tend to maintain the sleeves concentrieally true in respect to each other and to the body of the chuck. In other Words, the beveled bearings have a tendency under endpressure to center the sleeves and stem B,and thus counteract thetendency which the sleeves might have to get out ot' truth when contracted. l

In constructing a chuck in which the gripping of an extended portion of the stem ofthe tool is not needed there maybe butone slotted sleeve,as shown in Fig.5; but in this case also a portion, u, ofthe nut overlaps and ts truly on the plain end of the body ofthe chuck, for reasons above given; and l also prel'er in `this instance to bevel the shoulder p of the sleeve and adapt it to 'the beveled end p of thebody.

1 claim as my inventionl. A chuck in which the body A, having a threaded portion, c, and at and near its end a plain cylindrical portion, t, is combined with a slotted sleeve and with a nut adapted to the conical portion ot'the sleeve and to the threaded portion of the body, and constructed to it snugly on and overlap the plain cylindrical portion y ot' the said body, all substantially as set forth.

2. The combination of the threaded body of the chuck and its beveled end p with a split sleeve having a beveled shoulder, p, adapted to the beveled end of the body, and with the nut H, substantially as set forth.

3. A chuck in which two slotted sleeves, D and Gr, the cylindrical portion of one fitting into that ofthe other and each having a conical termination, are combined with the body A and nut H, substantially as set forth.

4. The combination of the slotted sleeve D, having a conical termination, d, and beveled shoulder m, the slotted sleeve G, having abeveled end, u, adapted to the said beveled shoulder ot' the sleeve D, the body A, and the nut H, all substantially as specified.

In testimony whereof l have signed my name to this specilicatiou in the presence ot' t\vo subscribing witnesses.

yGEORGE nnHFUss.

Witnesses:

HARRY DRURY, HARRY SMITH. 

